Island



i @uiten taies jatrut @ffice GEORGE F. WILSON, OF EAST PROVIDENCE, .RHODE ISLAND.

Leners Parent No. 75,826, .met armi, 1o, 186s.

IMPROVEMENT IN THEV PREPARATION 0F BONES FOB. THE MANUFAGTURE OPPHOSPHORIC ACID AND PHOSPHATES.

@La 5:11am: maar tr im time Eaters giganti nu mating nait at tige sima.

TO ALL WHOM IT MAY CONCERNf Be it known that l', GEORGE F. WILSON, of East Providence, in the county of Providence, and State o f Rhode Island,'havo invented anew and improvedProcess of Burning Bones Gray to Prepare them for the Extraction ot Acid Phosphate of Lime; and I hereby declare the following to be afull and exact description thereof, refer? ence being had to the accompanying drawing, and to the letters of reference marked thereon.

The object in this process is to prepare the bone so' that, when treated with diluted sulphuric acid, the resulting acid phosphate of lime and sulphate of lime may be readily separated by leaching. In order to this itis essential that the bones should not be burned to whiteness, blit to a certain uniform grayness, which experience has shown to be suited to the necessities of manufacture. If the burningstop short of thisl point there. remain sundry objectionable organic bodies, containing large measures ofthe elements of oiensive gases; if it be carried too far, the skeleton, so to speak, of each little fragment breaks down under the action of sulphuric acid, leaving a. pulp which rapidlyiills the interstices-of the felt or other iltcring-matcrial at the bottom of the leach, and so Yarrests or greatly retards the filtration. The desired point is reached when there remains suicicnt carbon to vpreserve the porous texture of the bone. i l

To accomplish the object proposed, bones are heated in closed cylinders or retorts, and the organic matters distilled till the residue attains the condition substantially as described in my'application forV a patent for au improvement in the distillation of bones, and of even date herewith. The bones are then quickly raked out into coolers, and excluded from the air to prevent their burning to whiteness, as described in the application above referred to. When cooled, the bones are ground to the ineness required for ordinary bone-black for sugar'.

reners. In this conditon the bones still contain cyanides, sulphides, and other organic compounds, which render of the carbon beyond a certain limit.

I find, by experiment, that when the gray bones,rai`ter being burned or roasted, are found to contain from ten to twelve per cent. of carbon, the remainder being chiey phosphate of lime, the best r'esult is produced. To accomplish this the coarse-grained powder is spread evenly, to a depth of three or four inches, over the floor of a furnace heated by ues underneath the bed as well as over the ceiling of the furnace. From time to time 4the mass of bone-black material is turned rapidly over with the aid of a long shovel or spatula. When the door' is opened for turning over the bones the outletfrom'thc furnace is closed, so as to cut oii' all draught over the surface of the bone. When the whole mass under treatment hasassumed the uniform grayish tint, indicating that thc proper constitution has been attained, the product is withdrawn from the furnace and laid aside ready for use. v l

The accompanying drawingsillustrate the structure oi' the furnace.

Figurefl presents a section parallel to the front of the furnace, with the airspace over the reverberating arch and the Hues under the sole. 1

Figure 2 presentabal section at right angles to that in iig. 1.

Figure B'exhibits a plan of the ilues under the sole, and

Figure 4 exhibits the flues over the chamber of the furnace.

The mode oi' operation is as follows: The bone to be treated in the furnace is such as has been previously prepared in accordance with the'speciiication of my application for Letters Patent, of even date herewith, the same being for an improvement in distilling bones, and having been thus prepared and subsequently ground up', the furnace is heated, the damper D closed, the sole S S is covered with ground bone, thus prepared, to a depth of three or four inches. The doorXto the furnace-chamber is then closed, and in this condition the whole body of b'one is brought to a glow. In a short time the upper surface parts withits surplus organic matters. The damper'l) is then closed, the dop X opened', and the bottom of the layer lturned uppermost with the aid of a spatula, as quickly as possible, to present new surface, and, as the spatula is withdrawn, the door X is immediatelyclosed and the damper Dopened.' This process is continued till the bone, which at the beginning was l e, s ff' l black, contains only about ten orv twelve per cent. of carbon, a result indicated bythe grayish appearance of the mass treated. It is then withdrawn from the furnace to loe eooled,'and is then ready for subsequent processes.

This furnace is contrived and operated so as to enable the operatorto remove, as far es possible, the cyanide's, sulphicles, and other offensive and injurious matters that may be present in the black hone, without removing more of the carbon than is desirable.

What I claim, and desire to secure by Letters Patent of the United States, is

1. My new .and improved process of burning and roasting bones gray, substantially as and for the purposes hereinbefore described, es preliminary to the extraction therefrom of acid phosphate of lime.

-2. I claim also, as an improvement in the process of preparing acid phosphate of lime, the use of bone-coal treated substantially as hereinbefore described.

3. I claim, also, the improved furnace,A constructed and operating substantially as and for the purposes as hereinbefore described.

GEO. F. WILSON.

Witnesses z WILLIAM I-IEDGE, W. H. MQGENERY.' 

